Suppose you have a one-frame video file
ffmpeg -i picture.ppm -vcodec libx264 -preset placebo -tune stillimage -crf 25 -y picture.mkv
and want to view it.
Here is a imlib2 plugin that uses ffmpeg to decode the first frame of the given video.
imlib2-webp was used as a imlib2 loader sample.
Semi-static (ffmpeg compiled in) linux x86 version is here.
Little bonus: simple ffmpeg usage function:
/* * Open the the file with FFmpeg, read the first video frame, convert it to RGBA image. * * returns malloc'ed buffer with the RGBA image on success and NULL on failure */ unsigned long* ffmpegsimple_readfirstframe(const char* filename, int *width, int *height);